Cutthroat/steelhead hybrid

I am hoping that one of our resident experts can help me out by identifying the characteristics that would be present in a hybrid. I may have caught one yesterday but am only beginning to think so after looking at the photo.
i remember something about teeth on the back of the tongue that someone has mentioned in the past but other than that i am clueless...
Any help would be appreciated.
:thumb:

Could you provide us with some more details? What makes you think it was a cutthroat/steelhead hybrid? Curt Kraemer believes that some of the largest sea-run cutthroat are hybrids. Can you post the picture?

Basibranchial teeth (formerly called hyoid teeth) which occur in cutthroat but not in rainbow/steelhead and are sometimes present in reduced size or numbers in hybrids, are represented by a small, triangular patch of teeth at the back of the tongue. They are easily felt by running a finger along the fish's tongue.

There are a number of things about the fish that made it unique.
Not many spots on the lower half of its body. (below the lat line)
very rose colored cheeks.
Longer snout
Shaped like a steelie- more long and slender, as opposed to the tanks that the larger cutts get to be.

The largest cutthroat I ever caught, or have even seen, was a 26-inch male taken from the Stillaguamish. If it was a hybrid it looked exactly like a coastal cutthroat. There is some thinking that cuttthroat/steelhead hybrids may be identified by the fact that they are usually in the 25-26-inch range. There seems to be a gap beween say a 20-inch mature cutthroat and then a skipping of about 21 to perhaps 24 inches to show up as monsters. The should not be taken as Gospel however.
Curt Kraemer has thoughts on this. He could probably add a bit more light on the subject.
Les Johnson

It is know that coastal cutthroat and steelhead can readily hybridize and the hybrids can also back cross with other cutts and steelhead or hybrids. However those back crosses are pretty rare.

A couple things that I found about the hybrids that I thought was interesting is that when sampling parr on various tributaries it was not uncommon that as many as 10% were hybrids. However even though we/I were looking for those hybrids I failed to identify most of them. Further it is pretty common to find a fair number of juvenile hybrids but not very many mature hybrids leading one to thing that those hybrids are at some sort of survival disadvantage. And if you think about they would almost have to be for the two species to maintain themselves as species.

One theory regading what sort of disadvantage a hybrid might have is that they don't know once they leave the river whether to behave/mirgate as cutt or steelhead and as result do more poorly than either of the two species.

Folks thing the most common way for hybridization to occur is when a female steelhead spawns with one or more cutthroat males. That is more likely to to happen in the smaller tributaries/streams. I also suspect hybridization is more likely when there are few steelhead.

The idea that the larger "cutts" could be hybrids is a long time theory of mine that to date has not been support by any "data". What I have noticed at least here on the North Puget Sound streams that while I have seen several exceptionally large cutts (fish in that 23 to 25 inch range) over the years I have seen very few at the next smaller size. On the waters that I have sampled it typically takes as many as 2 additional years of grow for a 17/18 inch fish to reach a honest 20 inches. Given that logic would dictate that be a lot more fish say 21 to 23 inches long than 23 to 25 inches. But that has not been the case. I have seen 8 or 10 times as many of those 23 to 25 inch fish as I have 21 to 23 inchers. My thinking is that those very large fish must be doing something different - either for some reason after 8 to 10 years of slow growth the suddenly grow 4 or 5 inches in a year or they are fish that have done something different their entire lives - hybrids?.

As Preston mentioned the best field test for a hybrid is to check for those hyoid teeth (at the back triangle of the tonque). Cutthroat have lots, steelhead none and the hybrids will have some but fewer and smaller that the cutts. The next time you catch a nice cutt just slide your finger across the surface of the tongue and you'll find them. However the best way would be through genetic testing - either scale or fin tissue can be collected without harming the fish.

Curt- thank you very much for the info. I have caught several fish in the 20-22 inch range (last year) but like you said, many of the larger cutts seem to stop growing longer once they reach a certain length.
When you say you were looking for hybrids but couldnt ID them, was it only through DNA that you were able to recognise them as hybrids?
I'd love to do some testing to learn more about the fish I catch. what i would really love to figure out is how far they travel and where the cutts I am catching are coming from. There are some big ones around most of the year but around this time each season there seems to be an influx of fish that have not been present over the summer.
Thank you very much for the input and let me know if you want to field test sometime.

D3
What I should have said was that while collecting cutthroat parr (4 to 6 inch fish) for genetic testing we also attempted to ID the hybrids. When the genetic results came back some of the fish that I had IDed as cutthroat were determined to have been hybrids. The genetic testing found more hybrids that what was identified visually though I suppose a more experienced "fish IDer" would have done better.

I suspect that south/central Sound and Hood Canal will likely be where a lot of potential hybrids especially adults will be found. If some researchers decides to delve into the issue of hybrids that would be a good place to focus the initial work.

Here is a fish that I caught last year, unfortunately the photo is over exposed but i thought this years fish was similar to last years. both have longer snouts and no marks on the gill plates.
Hybrid as well?

Sorry for the bad pics, had to steal them off facebook.

I would think it would be damn near impossible to ID a hybrid in the 4-6 inch range. they cant look too dissimilar at that stage of the game.
Any reason you would think the fish in the canal or s.sound would be a better place to look for hybrids? more opportunity or is there something else that would lead you to look there. All the fish i have caught that i would think of as classifying as hybrids have come from the central sound but maybe they are just passing through.
thank you as always.